Elevator belt and method of manufacture

ABSTRACT

A belt for suspending and/or driving an elevator car includes a plurality of tension elements extending along a length of the belt and a plurality of belt fibers transverse to the plurality of tension elements and interlaced therewith. The belt fibers define at least one traction surface of the belt. An edge fiber is located at a lateral end of the belt transverse to and secured to the plurality of belt fibers to secure the belt fibers in a selected position.

This application is a National Phases Application of Patent ApplicationPCT/US2014/016864 filed on Feb. 18, 2014, the entire contents of thisapplication is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to tension members such asthose used in elevator systems for suspension and/or driving of theelevator car and/or counterweight.

Conventional elevator systems use rope formed from steel wires as alifting tension load bearing member. Other systems utilize a liftingbelt formed from a number of steel cords, formed from steel wires,retained in an elastomeric jacket. The cords act as the load supportingtension member, while the elastomeric jacket holds the cords in a stableposition relative to each other, and provides a frictional load path toprovide traction for driving the belt.

Still other systems utilize woven belts, in which yarns or othernon-metallic fibers are woven together with the steel cords to retainthe cords. The woven belt is also saturated or coated with anelastomeric binder. This is done to produce a selected amount oftraction between the belt and a traction sheave that drives the belt,while reducing noise that sometimes results from the use of elastomericbelts. The steel cords in the woven belt are the primary load bearingtension members, the yarns and the binder material act to keep the cordsin place and provide a traction surface. The use of yarn materials alsoexpands the physical properties of the construction beyond what ispossible from thermoplastic or extrudable rubber jacket materials. Theseproperties include, but are not limited to, tensile strength, frictionproperties and flammability. In the woven belts, the yarns are orientedat angular orientations of 0 degrees and 90 degrees relative to thesteel cords, and the belt is assembled by a weaving process on a loom.The weaving process is inefficient and time consuming.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a belt for suspending and/or driving an elevator carincludes a plurality of tension elements extending along a length of thebelt and a plurality of belt fibers transverse to the plurality oftension elements and interlaced therewith. The belt fibers define atleast one traction surface of the belt. An edge fiber is located at alateral end of the belt and is secured to the plurality of belt fibersto secure the belt fibers in a selected position.

Alternatively or additionally, in this or other embodiments, the edgefiber includes adhesive to secure the edge fiber to the plurality ofbelt fibers.

Alternatively or additionally, in this or other embodiments, the edgefiber includes a thermally-activated material to secure the edge fiberto the plurality of belt fibers.

Alternatively or additionally, in this or other embodiments, the edgefiber extends parallel to the plurality of tension elements.

Alternatively or additionally, in this or other embodiments, theplurality of belt fibers is transverse to the plurality of tensionelements at a non-perpendicular angle.

Alternatively or additionally, in this or other embodiments, the angleis forty-five degrees.

Alternatively or additionally, in this or other embodiments, the tensionelements are formed from a first material and the belt fibers are formedfrom a second, different material.

Alternatively or additionally, in this or other embodiments, the tensionelements are formed from a metallic material and the belt fibers areformed from a non-metallic material.

Alternatively or additionally, in this or other embodiments, the beltfibers comprise a thermoplastic material.

Alternatively or additionally, in this or other embodiments, the beltfibers include thermoplastic filaments.

Alternatively or additionally, in this or other embodiments, the beltfibers are at least partially coated with an elastomeric material.

In another embodiment, a method of forming a belt for suspending and/ordriving an elevator car includes arranging a plurality of tensionelements along a length of the belt, defining a length of the belt andbraiding a plurality of belt fibers together with the plurality oftension elements to form a braided structure. The plurality of beltfibers extends transverse to the plurality of tension elements. An edgefiber is braided into the plurality of belt fibers at a lateral side ofthe braided structure, and the edge fiber is secured to the plurality ofbelt fibers to retain the weave fibers in a selected position.

Alternatively or additionally, in this or other embodiments, the edgefiber is heated to secure the edge fiber to the plurality of beltfibers.

Alternatively or additionally, in this or other embodiments, an edgefiber is braided into the plurality of belt fibers at each lateral sideof the braided structure.

Alternatively or additionally, in this or other embodiments, the edgefiber extends parallel to the plurality of tension elements.

Alternatively or additionally, in this or other embodiments, theplurality of belt fibers is transverse to the plurality of tensionelements at a non-perpendicular angle.

Alternatively or additionally, in this or other embodiments, the angleis forty-five degrees.

Alternatively or additionally, in this or other embodiments, a band ofselvage fibers are braided into the braided structure between adjacenttension elements of the plurality of tension elements.

Alternatively or additionally, in this or other embodiments, the selvagefibers are secured to the plurality of belt fibers.

Alternatively or additionally, in this or other embodiments, the braidedstructure is separated into two braided structures at the band ofselvage fibers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic of an exemplary elevator system having a 1:1roping arrangement;

FIG. 1B is a schematic of another exemplary elevator system having adifferent roping arrangement;

FIG. 1C is a schematic of another exemplary elevator system having acantilevered arrangement;

FIG. 2 is a plane view of an embodiment of an elevator belt;

FIG. 3 is a cross-sectional view of an embodiment of an elevator belt;

FIG. 4 is a plane view of another embodiment of an elevator belt;

FIG. 5 is a plane view of yet another embodiment of an elevator belt;

FIG. 6 is a plane view of still another embodiment of an elevator belt;

The detailed description explains the invention, together withadvantages and features, by way of examples with reference to thedrawings.

DETAILED DESCRIPTION OF THE INVENTION

Shown in FIGS. 1A, 1B and 1C are schematics of exemplary tractionelevator systems 10. Features of the elevator system 10 that are notrequired for an understanding of the present invention (such as theguide rails, safeties, etc.) are not discussed herein. The elevatorsystem 10 includes an elevator car 12 operatively suspended or supportedin a hoistway 14 with one or more belts 16. The one or more belts 16interact with one or more sheaves 18 to be routed around variouscomponents of the elevator system 10. The one or more belts 16 couldalso be connected to a counterweight 22, which is used to help balancethe elevator system 10 and reduce the difference in belt tension on bothsides of the traction sheave during operation.

The sheaves 18 each have a diameter 20, which may be the same ordifferent than the diameters of the other sheaves 18 in the elevatorsystem 10. At least one of the sheaves could be a traction sheave 52.The traction sheave 52 is driven by a machine 50. Movement of drivesheave by the machine 50 drives, moves and/or propels (through traction)the one or more belts 16 that are routed around the traction sheave 52.

At least one of the sheaves 18 could be a diverter, deflector or idlersheave. Diverter, deflector or idler sheaves are not driven by a machine50, but help guide the one or more belts 16 around the variouscomponents of the elevator system 10.

In some embodiments, the elevator system 10 could use two or more belts16 for suspending and/or driving the elevator car 12. In addition, theelevator system 10 could have various configurations such that eitherboth sides of the one or more belts 16 engage the one or more sheaves 18(such as shown in the exemplary elevator systems in FIG. 1A, 1B or 1C)or only one side of the one or more belts 16 engages the one or moresheaves 18.

FIG. 1A provides a 1:1 roping arrangement in which the one or more belts16 terminate at the car 12 and counterweight 22. FIGS. 1B and 1C providedifferent roping arrangements. Specifically, FIGS. 1B and 1C show thatthe car 12 and/or the counterweight 22 can have one or more sheaves 18thereon engaging the one or more belts 16 and the one or more belts 16can terminate elsewhere, typically at a structure within the hoistway 14(such as for a machineroomless elevator system) or within the machineroom (for elevator systems utilizing a machine room. The number ofsheaves 18 used in the arrangement determines the specific roping ratio(e.g. the 2:1 roping ratio shown in FIGS. 1B and 1C or a differentratio). FIG. 1C also provides a so-called rucksack or cantilevered typeelevator. The present invention could also be used on elevator systemsother than the exemplary types shown in FIGS. 1A, 1B and 1C.

The belts 16 are constructed to have sufficient flexibility when passingover the one or more sheaves 18 to provide low bending stresses, meetbelt life requirements and have smooth operation, while beingsufficiently strong to be capable of meeting strength requirements forsuspending and/or driving the elevator car 12.

FIG. 2 provides a schematic of an exemplary belt 16 construction ordesign. The belt 16 includes a plurality of tension elements 32. Asshown in FIG. 3, in some embodiments, the tension elements are cordsformed from a plurality of steel wires 36, which may be arranged intostrands 38. Referring again to FIG. 2, the tension elements 32 arearranged generally parallel to each other and extend in a longitudinaldirection that establishes a length of the belt 16. A plurality of beltfibers 40 that are braided together with the tension elements 32 into afabric that substantially retains the tension elements 32 has a selectedorientation relative to each other. The phrase “substantially retains”means that belt fibers 40 sufficiently engage the tension elements 32such that the tension elements 32 to not pull out of, or move relativeto, the belt fibers 40 in use of the belt 16.

Referring again to FIG. 3, the belt 16 includes a traction surface 42 onat least one side of the belt 16, and is defined by the belt fibers 40.Having the traction surface 42 defined by the belt fibers 40 includesthe belt fibers 40 being exposed at the traction surface 42, a coatingover the belt fibers 40 having a surface contour defined by the presenceof the belt fibers 40, or a combination of these.

The tension elements 32 are the primary load bearing structure of theelevator belt 16. In some embodiments, the belt fibers 40 do not supportthe weight of the elevator car 12 or counterweight 22. Nevertheless, thebelt fibers 40 do form part of the load path. The belt fibers 40transmit the traction forces between the traction sheave 52 and the belt16 to the tension elements 32. Such traction force transmission in someexamples is direct (e.g. when the belt fibers 40 are exposed at thetraction surface 42) or indirect (e.g. when the belt fibers 40 arecoated and the coating establishes the exterior of the traction surface42).

The belt fibers 40 are arranged in a pattern relative to the tensionelements 32 so that a spacing between the traction surface 42 and thetension elements 32 prevents the tension elements 32 from contacting acomponent that the traction surface 42 engages. For example, the tensionelements 32 will not contact a surface on the traction sheave 52 as thebelt 16 wraps at least partially around the traction sheave 52. The sizeof the belt fibers 40, the material of the belt fibers 40, the patternof the belt fibers 40 or a combination of these is selected to ensurethe desired spacing between the tension elements 32 and the tractionsurface 42 so that the tension elements 32 are protected from directengagement with a component such as the traction sheave 52. In oneembodiment, a coating over the belt fibers 40 protects the weave fibers40 and therefore ensures that the tension elements 32 are sufficientlyspaced from the traction surface 42 so that the tension elements 32 willnot directly engage or come into contact with the traction sheave 52 oranother sheave 18 of the elevator system.

In an embodiment, the tension elements 32 are formed from a firstmaterial, such as drawn steel, and the belt fibers 40 are formed from asecond, different material and have a much smaller thickness and/orcross-sectional dimension compared to the tension elements 32. The beltfibers 40 may be formed from, for example, a nonmetallic material suchas a polymer. In some embodiment, the belt fibers 40 include athermoplastic material that is useful for establishing the tractionsurface 42. One embodiment includes forming the belt fibers 40, thencoating the belt fibers 40 with the elastomeric material. In anotherembodiment, the belt fibers 40 are formed, braided to the tensionelements 32, then selectively coated with the elastomeric material. Instill another embodiment, the belt fibers 40 are formed from a pluralityof filaments, with at least one of the filaments including thethermoplastic material.

The belt fibers 40 are oriented at a non-perpendicular angle to thetension elements 32, for example, at +/−60 degrees or +/−45 degreesrelative to the tension elements. Further, the belt fibers 40 mayinclude first belt fibers 40 a orientated at a first angle relative tothe tension elements 32 and second belt fibers 40 b oriented at a secondangle relative to the tension elements 32. Braiding with the belt fibers40 oriented at angles other than 0 and 90 degrees relative to thetension elements 32 provides a tightening effect when as the belt 16 isformed, as well as when the belt 16 is initially put into service and aload is applied to it. The tightening improves dimensional stability ofthe belt 16 as well as greater control over traction of the belt 16during operation. Thermoplastic, elastomeric, adhesive and/orthermally-activated materials may be included in the belt 16 to improvedimensional and physical properties of the belt 16.

Referring now to FIG. 4, in addition to the belt fibers 40 and thetension elements 32, the belt 16 includes edge fibers 46 extending alongthe length of the belt 16 substantially parallel to the tension elements32. The edge fibers 46 may be formed from an adhesive orthermally-activated material, which when set, secures the positions ofthe belt fibers 40, preventing the belt 16 from fraying or unraveling atthe edges. In some embodiments, the edge fibers 46 may be mechanicallyclosed around the belt fibers 40 by, for example, tying, to secure theedge fiber 46 and belt fiber 40 position.

Referring now to FIGS. 5 and 6, the braiding arrangement of the beltfibers 40 allows for the simultaneous manufacturing of multiple belts16. Tension elements 32 for two or more belts 16 are arrangedside-by-side, along with edge fibers 46 at the edges, and a band ofselvage fibers 48, or alternatively, additional edge fibers 46 betweenadjacent tension elements 32. The belt fibers 40 a and 40 b are braidedthrough the edge fibers 46, tension elements 32 and selvage fibers 48defining a single braided structure. The edge fibers 46 and selvagefibers 48, if needed, are activated by, for example, application ofheat, to secure the belt fibers 40 a and 40 b in place. Finally, thebraided structure is separated into two or more belts 16, as shown inFIG. 6, by cutting or otherwise separating the structure between theselvage fibers 48. Manufacturing of more than one belt 16 at a timeutilizing this method increases efficiency of fabrication and reducesmaterial waste in fabrication. While the embodiment illustrated producestwo belts 16 simultaneously, one skilled in the art will recognize thatsuch method may be used to fabricate 3, 4 or more belts 16simultaneously.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

The invention claimed is:
 1. A belt for suspending and/or driving anelevator car, comprising: a plurality of metallic tension elementsextending along a length of the belt; a plurality of non-metallic beltfibers transverse to the plurality of tension elements and braidedtherewith, the belt fibers defining at least one traction surface of thebelt; and a non-metallic edge fiber disposed at a lateral end of thebelt transverse and secured to the plurality of belt fibers to securethe belt fibers in a selected position, the edge fiber including athermally-activated material, which when set secures the edge fiber tothe plurality of belt fibers, the edge fiber disposed parallel to theplurality of tension elements, the non-metallic edge fiber mechanicallyclosed around the plurality of belt fibers.
 2. The belt of claim 1,wherein the edge fiber includes adhesive to secure the edge fiber to theplurality of belt fibers.
 3. The belt of claim 1, wherein the pluralityof belt fibers are transverse to the plurality of tension elements at anon-perpendicular angle.
 4. The belt of claim 3, wherein the angle isforty-five degrees.
 5. The belt of claim 1, wherein the tension elementsare formed from a first material and the belt fibers are formed from asecond, different material.
 6. The belt of claim 5, wherein the tensionelements are formed from a metallic material and the belt fibers areformed from a non-metallic material.
 7. The belt of claim 1, wherein thebelt fibers comprise a thermoplastic material.
 8. The belt of claim 7,wherein the belt fibers include thermoplastic filaments.
 9. The belt ofclaim 7, wherein the belt fibers are at least partially coated with anelastomeric material.